Implantation of artificial lenses into the human eye has been a standard technique for many years, both to replace the natural crystalline lens (aphakic eye) and to supplement and correct refractive errors of the natural lens (phakic eye).
Various diseases and pathological conditions can result in damage to the natural crystalline lens, such as opacification that occurs as a result of cataracts. Intraocular artificial lens implantation into the anterior chamber or posterior chamber of the eye is a known technique for treating cataracts.
Intraocular corrective lenses have been developed for the treatment of various vision problems of the eye, such as myopia, hyperopia and astigmatism in the phakic eye. However, the use of currently available phakic intraocular lenses has been less than satisfactory in the long-term correction of refractive errors because the overall design of these lenses can result in damage to the natural crystalline lens.
The ideal phakic intraocular lens must be implantable through a self-scaling, clear corneal incision. It must be made of a very biocompatible material. It must have minimal touch with the uveal structures of the eye, no contact with the natural crystalline lens, and no compromise of the angle of the eye.
Currently, most phakic lenses are iris-fixated lenses, angle-fixated lenses, or sulcus-fixated, posterior chamber lenses.
Iris-fixated lenses require a 5.5 to 6 mm incision and involve a difficult insertion surgical technique. Angle-fixated lenses generally a 5.5 mm incision. These lenses also require very accurate white-to-white measurements, which are difficult to obtain. Angle-fixated lenses can also cause pupillary distortion. Sulcus-fixated/posterior chamber lenses are less difficult surgically to insert than iris-fixated lenses, but are more difficult to inset than angle-fixated lenses. There have been reports of cataract formation after insertion of these lenses.
Examples of implantable intraocular lenses include various design configurations. Generally, the lenses are attached in some manner within the eye, usually by sutures to the iris, or some other supporting means, such as arms, or haptics, extending from the optical lens portion of the intraocular lens.
U.S. Pat. No. 4,053,953 describes an artificial intraocular lens for the aphakic eye. The lens is secured in the posterior chamber by a system of posts that protrude through the iris attached to retaining rings.
U.S. Pat. No. 6,015,435 describes a self-centering phakic intraocular lens inserted in to the posterior chamber lens for the correction of myopia, hyperopia, astigmatism, and presbyopia. Haptic bodies are attached to optical body and extend outward from tangent points at the edge of lens in at least two generally opposite directions. Protruding surfaces protrude into pupil such that the iris interferes slightly with lens movement and provides the centering force to keep lens in place.
U.S. Pat. No. 4,710,195 describes a posterior chamber lens, particularly adapted for patients with glaucoma and cataracts. Two haptics are connected to optic body at its edge. The haptics are offset from the other by 180 degrees and extend circumferentially around the edge of the optic portion. The haptics end in enlarged "blocking segments".
U.S. Pat. No. 4,676,792 describes an artificial intraocular lens device implantable in the anterior chamber of the eye (in front of the iris) for treating myopia. The optic body has three or four "J" shaped haptics that terminate with solid footplates to anchor the lens. In one embodiment, haptics are positioned circumferentially around the edge of optic body approximately 90 degrees apart. The haptics are grouped in pairs so that each pair is oriented such that the respective curved surfaces of solid footplates face each other.
U.S. Pat. No. 5,133,747 describes an intraocular lens device that is partially or completely within the anterior capsular surface of the human crystalline lens. In one embodiment, the optic body has asymmetrical haptics extending outwardly from opposite sides of the periphery of the optic body. In one embodiment, "J" shaped haptics extend from the periphery of the optic body in a manner that encircles optic body. In another configuration, the haptics extend tangentially away from body, then reverse direction, giving the device an overall "S" shape with the lens at center portion of the S. The device is secured in place with an adhesive.
U.S. Pat. No. 5,928,282 describes a refractive intraocular lens for implantation into the anterior chamber. The lens body has elongated, ovoid-disc shaped haptics extending from its peripheral edge.
U.S. Pat. No. 4,994,080 describes optical lens devices having an optical body with multiple perforations and two J shaped haptics that terminate in footplates.
U.S. Pat. No. 6,083,261 describes an intraocular lens having crossed haptics for implantation into either phakic or aphakic eye.
U.S. Pat. No. 4,285,072 describes closed loop haptics on an intraocular lens. When positioned in the eye, the circular arched haptics without footplates extend rearward from the optic body, then angle sideways to allow the arch to rest in the angle to keep the lens in place. This design proved to be physiologically unsuitable for use.
There is a need for an intraocular lens device that overcomes the problems of the existing intraocular lenses and yet provides ophthalmic surgeons with an intraocular lens that addresses the refractive errors in patients' eyes safely and reversibly.